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Salut !
a)
- x(x+5) = x²+5x
- x(x+3) = x²+3x
- (x+3)(x+5) = x²+8x+15
b) 2(x²+5x)+2(x²+3x)+2(x²+8x+15) = 6x²+32x+30
c) 6(5²)+32(5)+30 = 340
Salut !
a)
b) 2(x²+5x)+2(x²+3x)+2(x²+8x+15) = 6x²+32x+30
c) 6(5²)+32(5)+30 = 340